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Functionalized activated carbon for the adsorptive removal of perchlorate from water solutions

Rovshan MAHMUDOV, Chinglung CHEN, Chin-Pao HUANG

《化学科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 194-208 doi: 10.1007/s11705-015-1517-3

摘要: Two types of activated carbon, namely, Filtrasorb 400 and Nuchar SA, were functionalized by quaternary ammonium salts (quats), as to enhance perchlorate adsorption. Results showed that the adsorption of quats on Nuchar SA increased with increase in chain length (hydrophobicity) of quats. Filtrasorb 400, however, had limited uptake of long-chain quats such as dodecyltrimethylammonium and hexadecyltrimethylammoium (HDTMA). Results indicated that perchlorate removal by the functionalized activated carbon was directly related to the chain length of the modifying quats. Perchlorate removal by functionalized activated carbon increased with increase in chain length of the modifying quats and became less pH-dependent. Modified Nuchar SA had higher overall perchlorate removal capacity than the modified Filtrasorb F400, but was more strongly affected by pH than Filtrasorb 400. Activated carbon treated with HDTMA exhibited the best perchlorate removal capacity among all quats studied. Results indicated that tailoring the activated carbon surface with HDTMA rendered the activated carbon surface positively charged, which resulted in substantial increase in perchlorate removal compared to unfunctionalized activated carbons.

关键词: perchlorate     activated carbon     removal     functionalization     quaternary ammonium salts    

Process control factors for continuous microbial perchlorate reduction in the presence of zero-valent

ARTHUR Robert D.,TORLAPATI Jagadish,SHIN Kyung-Hee,CHA Daniel K.,YOON Yeomin,SON Ahjeong

《环境科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 386-393 doi: 10.1007/s11783-013-0593-1

摘要: Process control parameters influencing microbial perchlorate reduction via a flow-through zero-valent iron (ZVI) column reactor were investigated in order to optimize perchlorate removal from water. Mixed perchlorate reducers were obtained from a wastewater treatment plant and inoculated into the reactor without further acclimation. Examined parameters included hydraulic residence time (HRT), pH, nutrients requirement, and perchlorate reduction kinetics. The minimum HRT for the system was concluded to be 8 hr. The removal efficiency of 10 mg·L influent perchlorate concentration was reduced by 20%–80% without control to the neutral pH (HRT= 8 hr). Therefore pH was determined to be an important parameter for microbial perchlorate reduction. Furthermore, a viable alternative to pH buffer was discussed. The microbial perchlorate reduction followed the first order kinetics, with a rate constant ( ) of 0.761 hr . The results from this study will contribute to the implementation of a safe, cost effective, and efficient system for perchlorate reduction to below regulated levels.

关键词: perchlorate     zero-valent iron (ZVI)     microbial reduction     hydrogen    

Recent advances in SERS detection of perchlorate

Jumin Hao, Xiaoguang Meng

《化学科学与工程前沿(英文)》 2017年 第11卷 第3期   页码 448-464 doi: 10.1007/s11705-017-1611-9

摘要: Perchlorate has recently emerged as a widespread environmental contaminant of healthy concern. Development of novel detection methods for perchlorate with the potential for field use has been an urgent need. The investigation has shown that surface-enhanced Raman scattering (SERS) technique has great potential to become a practical analysis tool for the rapid screening and routine monitoring of perchlorate in the field, particularly when coupled with portable/handheld Raman spectrometers. In this review article, we summarize progress made in SERS analysis of perchlorate in water and other media with an emphasis on the development of SERS substrates for perchlorate detection. The potential of this technique for fast screening and field testing of perchlorate-contaminated environmental samples is discussed. The challenges and possible solutions are also addressed, aiming to provide a better understanding on the development directions in the research field.

关键词: perchlorate     SERS     detection     substrate     modification     nanostructure    

Recent advances in the electrochemical oxidation water treatment: Spotlight on byproduct control

Yang Yang

《环境科学与工程前沿(英文)》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1264-7

摘要: Abstract • Byproduct formation mechanisms during electrochemical oxidation water treatment. • Control byproduct formation by quenchers. • Process optimization to suppress byproduct formation. Electrochemical oxidation (EO) is a promising technique for decentralized wastewater treatment, owing to its modular design, high efficiency, and ease of automation and transportation. The catalytic destruction of recalcitrant, non-biodegradable pollutants (per- and poly-fluoroalkyl substances (PFAS), pharmaceuticals, and personal care products (PPCPs), pesticides, etc.) is an appropriate niche for EO. EO can be more effective than homogeneous advanced oxidation processes for the degradation of recalcitrant chemicals inert to radical-mediated oxidation, because the potential of the anode can be made much higher than that of hydroxyl radicals (EOH = 2.7 V vs. NHE), forcing the direct transfer of electrons from pollutants to electrodes. Unfortunately, at such high anodic potential, chloride ions, which are ubiquitous in natural water systems, will be readily oxidized to chlorine and perchlorate. Perchlorate is a to-be-regulated byproduct, and chlorine can react with matrix organics to produce organic halogen compounds. In the past ten years, novel electrode materials and processes have been developed. However, spotlights were rarely focused on the control of byproduct formation during EO processes in a real-world context. When we use EO techniques to eliminate target contaminants with concentrations at μg/L-levels, byproducts at mg/L-levels might be produced. Is it a good trade-off? Is it possible to inhibit byproduct formation without compromising the performance of EO? In this mini-review, we will summarize the recent advances and provide perspectives to address the above questions.

关键词: Electrochemical water treatment     Byproducts     Perchlorate    

Nexus between polymer support and metal oxide nanoparticles in hybrid nanosorbent materials (HNMs) for sorption/desorption of target ligands

Ryan C. SMITH,Jinze LI,Surapol PADUNGTHON,Arup K. SENGUPTA

《环境科学与工程前沿(英文)》 2015年 第9卷 第5期   页码 929-938 doi: 10.1007/s11783-015-0795-9

摘要: Metal oxide nanoparticles like hydrated ferric oxide (HFO) or hydrated zirconium oxide (HZrO) are excellent sorbents for environmentally significant ligands like phosphate, arsenic, or fluoride, present at trace concentrations. Since the sorption capacity is surface dependent for HFO and HZrO, nanoscale sizes offer significant enhancement in performance. However, due to their miniscule sizes, low attrition resistance, and poor durability they are unable to be used in typical plug-flow column setups. Meanwhile ion exchange resins, which have no specific affinity toward anionic ligands, are durable and chemically stable. By impregnating metal oxide nanoparticles inside a polymer support, with or without functional groups, a hybrid nanosorbent material (HNM) can be prepared. A HNM is durable, mechanically strong, and chemically stable. The functional groups of the polymeric support will affect the overall removal efficiency of the ligands exerted by the Donnan Membrane Effect. For example, the removal of arsenic by HFO or the removal of fluoride by HZrO is enhanced by using anion exchange resins. The HNM can be precisely tuned to remove one type of contaminant over another type. Also, the physical morphology of the support material, spherical bead versus ion exchange fiber, has a significant effect on kinetics of sorption and desorption. HNMs also possess dual sorption sites and are capable of removing multiple contaminants, namely, arsenate and perchlorate, concurrently.

关键词: ion exchange     sorption     arsenic     perchlorate     fluoride    

标题 作者 时间 类型 操作

Functionalized activated carbon for the adsorptive removal of perchlorate from water solutions

Rovshan MAHMUDOV, Chinglung CHEN, Chin-Pao HUANG

期刊论文

Process control factors for continuous microbial perchlorate reduction in the presence of zero-valent

ARTHUR Robert D.,TORLAPATI Jagadish,SHIN Kyung-Hee,CHA Daniel K.,YOON Yeomin,SON Ahjeong

期刊论文

Recent advances in SERS detection of perchlorate

Jumin Hao, Xiaoguang Meng

期刊论文

Recent advances in the electrochemical oxidation water treatment: Spotlight on byproduct control

Yang Yang

期刊论文

Nexus between polymer support and metal oxide nanoparticles in hybrid nanosorbent materials (HNMs) for sorption/desorption of target ligands

Ryan C. SMITH,Jinze LI,Surapol PADUNGTHON,Arup K. SENGUPTA

期刊论文